Preparation

Make the cake:

• 机架位置在烤箱底部的三分之一d heat the oven to 350°F. Butter and flour a 9×13-inch heavy-duty metal cake pan. Soak the currants in 1/2 cup hot tap water for 15 minutes. Drain and set aside.
• In a food processor (use the steel blade), chop the carrots very finely to about the consistency of couscous. Transfer to a small bowl and rinse the food processor bowl (you’ll need it again).
• In a large bowl, combine the flour, baking soda, salt, and spices. Whisk to blend thoroughly. Transfer 1/4 cup of this mixture to a small bowl and add the drained currants and the 3 oz. nuts. Toss to combine.
• In the food processor (again use the steel blade), mix the eggs and sugars until blended. With the machine running, slowly add the oils in a steady stream until combined. Scrape this mixture into the flour mixture. Stir with a wooden spoon or rubber spatula to combine. Add the carrots and the raisin-nut mixture; stir to combine.
• Scrape the batter into the prepared pan. Bake until a toothpick inserted in the center of the cake comes out clean, about 50 minutes. Let cool on a rack to room temperature before inverting the pan to remove the cake. Let cool completely before frosting.

Make the frosting:

• Fit a stand mixer with the paddle attachment (a hand mixer works, too). Beat the butter on medium speed until it’s quite light, fluffy, and resembles whipped cream, about 3 minutes. Add the cream cheese one piece at a time, beating well after each addition. When all the cream cheese is incorporated, reduce the speed to medium low and gradually add the sugar and vanilla, stopping the mixer each time you add the sugar. Mix just enough to remove any lumps; scrape the bowl as needed. If the frosting seems a bit loose, refrigerate it for a few minutes until it seems spreadable.

Frost the cake:

• Scrape about two-thirds of the frosting onto the center of the cake. With a narrow metal offset spatula, push the frosting from the center out to and just over the cake’s edges. Spread with as few strokes as possible to prevent crumbs from catching in the frosting. Cover the top of the cake first then use the remaining frosting along with what’s creeping over the edges of the cake to cover the sides. Once the cake is covered, drag the front tip of the spatula back and forth from end to end to create a textured surface on the top of the cake. If you like, sprinkle the nuts on top of the cake and press them into the sides.